One hundred ninety-nine species of bryophytes are documented for Erie County, Pennsylvania, representing 34% of the Pennsylvania bryophyte flora. This work is the result of scattered surveys over multiple years and the 2012 Crum Workshop. Aneura maxima, Calypogeia integristipula, C. sphagnicola, Fuscocephaloziopsis loitlesbergeri, F. macrostachya, F. pleniceps, Cephaloziella hyalina, and Campylium protensum are reported new to the state, and an 83 species are reported new for the county. Nearly 40% of the species on this list are considered “rare” and tracked as critically imperiled (S1), imperiled (S2), or vulnerable (S3) by Pennsylvania Natural Heritage Program, highlighting the critical role of intensive surveys for bryophyte conservation.